With large swaths of dense smog blanketing much of eastern China, officials have informed pilots flying to Beijing that they must first undertake special qualifications for landing in low visibility.

According to the state-run China Daily newspaper, pilots flying from any of the country’s ten busiest airports to Beijing must be qualified to land using just their flight instruments in the event that excessive pollution slashes visibility to just 400 meters.

“It is part of a series of measures the administration took recently to raise the flights’ on-time performance,” read the article, according to Reuters.

China’s airports are infamous for massive delays, while the increased consumption of coal during the winter months in the country’s north is responsible for enveloping the area with thick clouds of smog.